Thousands of protesters living near a nuclear power plant about to be commissioned are blocking highways and staging hunger strikes demanding its closure as they distrust federal government assurances regarding safety.

Agitated villagers living around the Russian-built Koodankulam nuclear plant in the southern Tamil Nadu province, 700km south of the state capital of Chennai, fear there will be an accident similar to the radiation leak in March at Japan's Fukushima nuclear plant following the earthquake and tsunami.

They have blocked all entry points to the plant, preventing further construction work.

"The nuclear plant is unsafe," said SP Udayakumar, of the voluntary People's Movement Against Nuclear Energy. "The safety analysis report and the site evaluation study have not been made public. No public hearing was held. It's an authoritarian project that has been imposed on the people."

He said there had been serious lapses in the environmental impact assessment and that a report commissioned by the Russian Government had found 25 defects in the reactor design.

The report concluded that the Russian technology was unsafe and that the reactors were not equipped to withstand natural or man-made disasters.

India, which has 20 civilian atomic plants, plans on quadrupling its 5000 megawatts of power - barely 2.3 per cent of its current energy output - by 2020 to fuel its booming economy.

Following the Fukushima catastrophe, the debate in India over harnessing nuclear power has become intense, with politicians, atomic scientists, analysts and writers ranged on either side.

This applies not only to the Koodankulam plant, under construction for more than a decade and expected to begin operations soon, but to a series of similar plants planned for India, with possible United States, French and Russian collaboration.

Prime Minister Manmohan Singh told Tamil Naud Chief Minister J Jayalalitha that all precautions would be taken at the Koodankulam nuclear plant to maintain the highest safety standards.

"The Government fully shares the concerns of the people of the area and will take all steps to allay their fears" Singh said, emphasising that Indian nuclear reactors had an impeccable safety record.

But that has failed to mollify Jayalalitha or People's Movement members, who remain opposed to the plant.

Udayakumar said: "We feel that India should not go for nuclear energy when developed countries such as Germany and Italy are phasing out their reactors.

"Even if they open nuclear plants like shops across the country, we are not going to produce more than 10 per cent of power.

"It will take 24,000 years to dispose of half the nuclear waste these would generate."